EP2701974B1

EP2701974B1 - High lift component for an aircraft, high lift system, method for adjusting the high lift characteristics of an aircraft and aircraft

Info

Publication number: EP2701974B1
Application number: EP12718964.5A
Authority: EP
Inventors: Bernhard Schlipf; Xavier Hue
Original assignee: Airbus Operations GmbH
Current assignee: Airbus Operations GmbH
Priority date: 2011-04-28
Filing date: 2012-04-27
Publication date: 2018-11-21
Anticipated expiration: 2032-04-27
Also published as: US9567064B2; EP2701974A2; CN103492263A; WO2012146705A3; CN103492263B; US20140048656A1; WO2012146705A2; DE102011018907A1

Description

TECHNICAL FIELD

The invention relates to a high lift component for an aircraft, to a high lift system, to a method for adjusting the high lift characteristics of an aircraft, and to an aircraft.

BACKGROUND TO THE INVENTION

In order to reduce takeoff and landing speeds, modern commercial aircraft frequently comprise high lift components which when required effect a significant increase in the surface of a wing and its curvature. Apart from single-part and multi-part trailing edge flaps of various designs, there are also slats, leading edge flaps and nose flaps on the wing leading edge. Because of the wingspan of larger aircraft, a profile thickness that decreases towards the outside, and sometimes a different movement path between the outside and the inside of leading edge flaps, such high lift components are usually segmented. The individual segments are individually moved.
It is known to arrange intermediate seals between adjacent segmented high lift components, which intermediate seals close the gap between the high lift components. Consequently, adjacent high lift components form an essentially uninterrupted contour so that the performance of the high lift system is improved because gap flows can be largely avoided.
At the same time, the state of the art shows that in particular in larger wingspans, gaps between adjacent high lift components are increased during deflection of the wing to such an extent that intermediate seals arranged therein are no longer able to completely close the gap. This results in performance losses in the high lift system.
WO 2008/129074 A1 discloses an aircraft having a fuselage, an airfoil mounted to the fuselage, a flap for steering the aircraft and a rod for articularly connecting the flap to the airfoil. The flap is allowed to rotate around a rotation axis substantially parallel to the trailing or leading edge of the airfoil between a retracted position and an extended position and to translate in a direction substantially parallel to the rotation axis.

PRESENTATION OF THE INVENTION

It is thus an object of the invention to propose an improved high lift component or an improved high lift system for improving the performance by means of improved intermediate seals. The performance should remain constant, to the largest extent possible, even in the case of different displacement speeds of adjacent high lift components and even in the case of considerable deflection of the wing.
The object relating to the high lift component is met by a high lift component with the characteristics of the independent claim 1. Advantageous improvements are shown in the subordinate claims.
A central idea of the invention consists of providing a high lift component according to the present invention on at least one lateral surface with an intermediate seal comprising at least one hollow body made of an elastic material, wherein the hollow body comprises a fluid inlet that can be connected to a fluid source.
The term "high lift component" refers to a lift body that comprises two lateral surfaces and that can be moved, by way of an actuator, drive kinematics or some other devices, in a predetermined manner to a wing in order to achieve an increase in the lift of the wing. The high lift component can be implemented in a variety of ways. If the high lift component is designed as a Krueger flap, it is preferably pivotably held at an end or in an end region, and can be deflected from the underside of the wing in the direction of flight into the airstream. In contrast to this, a slat can be moved along a movement path from a leading edge section of the wing, in a translatory manner along a curved path, in such a manner into the airflow that a gap arises between the slat and the leading edge section of the wing. A nose flap, in turn, is to be regarded as part of the wing, which part can essentially be pivoted on a hinge axis in order to increase the curvature of the wing. In principle, a high lift component can also be designed as a trailing edge flap which can be moved, for example in the form of a Fowler flap, along a predetermined movement path from the wing end to the direction of flow in order to increase the curvature and surface of the wing. Furthermore, double-gap flaps are known that in a manner similar to that of a Fowler flap can be moved away from a wing trailing edge in order to form two gaps to the wing trailing edge.
Basically all these high lift components comprise more or less pronounced lateral surfaces that form a gap to adjacent lateral surfaces of adjacent high lift components. This gap is necessary in order to avoid mechanical damage of the high lift components from occurring during independent actuation. It is the purpose of the intermediate seal according to the invention with a hollow space comprising an elastic material to fill in and to increase or decrease in an autonomous manner according to requirements in the case of changes to the gap geometries by elastic deformation of the hollow body with fluid contained in the hollow body. By applying fluid pressure to the fluid inlet, in the case of an increase in the space available, in the gap, for the intermediate seal, the hollow body is expanded by way of the fluid source so that said hollow body extends from the lateral surface towards the outside where it butts against a corresponding intermediate seal or an adjacent lateral surface of an adjacent high lift component.
With the use of an elastic material, on the one hand the ability of the intermediate seal to expand is provided, and on the other hand an intermediate seal designed in this manner is also sufficiently flexible so that it can be compressed by external mechanical action. If there is such an intermediate seal between two high lift components, and if the wing deflects to such an extent that the gap between the high lift components would be reduced, the corresponding intermediate seal can be squeezed. However, this does not result in the intermediate seal being damaged; instead, after the wing has swung back the intermediate seal can expand again and can also fill in any gap that may be of increased size.
Any sources of a fluid with a pressure higher than the respective ambient pressure of the high lift component can be considered as fluid sources. In a particularly simple manner in the case of an aircraft an air source may be used that may already be present in the form of ram air inlets, cooling air outlets, bleed air systems or the like, and which by means of a suitable line may be able to be connected to the intermediate seal of the high lift component. As an alternative it would also be possible to use dedicated pumps or blowers. If liquid fluids are selected for the expansion of the intermediate seal, it should be noted that this fluid remains liquid in the entire operating temperature range and that the hollow body is protected from damage as a result of crystal formation or excessive expansion during solidification, or excessive pressure during vaporization.
In an advantageous embodiment of the invention the hollow body of the intermediate seal is a hose-like body that is arranged along a largely closed path on the lateral surface of the high lift component. In this manner the largest possible circumferential distance is formed, which provides good coverage of the gap. A gap that tapers off results in a redistribution of fluid from the narrowing gap end to the widening gap end.
In an advantageous embodiment of the invention the high lift component comprises an upper outer surface which, for example, at least in some regions faces upstream in operation, and a lower outer surface which, for example, at least in some regions faces downstream in operation, wherein a passage extends from the lower or from the upper surface to the high lift component, and wherein the end situated in the interior of the high lift component is connected to the fluid connection. This design is associated with particular advantages in relation to high lift components comprising a lower surface and an upper surface, wherein one of these surfaces is not in direct fluidic contact with the surroundings. The passage concerned is preferably arranged in this surface so that with the high lift system deactivated, and consequently with the high lift component retracted, on the one hand the passage is protected against the surroundings, and on the other hand does not have any influence on the airflow around the wing. When the high lift component concerned is pivoted out or extended, the passage establishes fluidic contact with the surrounding airflow so that the pressure applied to the passage depends on the airflow around the high lift component. The position of the passage is to be selected in such a manner that in the extended state of the high lift component the pressure is higher than the static ambient pressure, and consequently with the high lift component extended, the hollow body is automatically pressurized from the passage. Consequently there is no need to provide active fluid sources.
In an advantageous embodiment the high lift component is designed as a Krueger flap which at its lower outer surface in its extended state comprises a passage that is connected to the fluid connection. With the Krueger flap extended, the hollow bodies of the intermediate seal are inflated and press towards any adjacent Krueger flaps.
In an advantageous embodiment of the invention the passage is connected to a valve. The valve can be a nonreturn valve or a switching valve that is connected to a control unit, and if required can feed the fluid from the passage to the hollow body. In this way it can be ensured that the hollow bodies are filled only if and when necessary. The switching valve may be controlled automatically or manually, either by a pilot or in an automated manner when an extended position of the high lift component has been reached.
In a further advantageous embodiment the fluid source is designed as a pitot tube that is located on an outside of the high lift component, of the superordinate wing or of some other part of the aircraft concerned, and which is connected to the fluid inlet of the hollow body by way of a fluid line.
In an advantageous embodiment the hollow body is of a hose-like design, comprises two closed ends, and extends along a path on the lateral surface of the high lift component, which path on the border extends along the upper outer surface and a wing leading edge. Such a design makes sense, in particular, in the case of very slender profiles that comprise only a very thin profile thickness.
In an advantageous embodiment of the invention the hollow body is arranged so as to be largely flush with the profile contour so that as flush as possible a closure of the gap is achieved.
The object relating to the high lift system is met by a high lift system that comprises at least one intermediate seal that comprises at least one hollow body made of an elastic material, which hollow body comprises a fluid inlet that is connectable to a fluid source.
The object relating to the aircraft is met by an aircraft comprising at least one high lift component as mentioned above.
The object relating to the method is met by the method according to claim 10 for adjusting the high lift characteristics of an aircraft, with the method comprising the steps of extending two adjacent high lift components of the aircraft from a retracted position to an extended position and expanding at least one intermediate seal that in the extended position of both high lift components is located between the high lift components so that in the extended position of the high lift components the at least one intermediate seal is expanded in such a manner that the space between the high lift components is essentially closed by the at least one intermediate seal. Preferably, expansion takes place by introducing fluid into at least one hollow body of the intermediate seal, wherein in an advantageous embodiment this can also include introducing ram air that can originate from a passage that projects into the high lift component or from a pitot tube. By controlling a valve it is possible to achieve a selective introduction of fluid.

BRIEF DESCRIPTION OF THE DRAWINGS

Figs 1a to 1c show an overall view (Fig. 1a) of a wing with high lift components, and detailed views of the region between the high lift components (Figs 1b and 1c).
Figs 2a and 2b show a three-dimensional view of two exemplary embodiments of intermediate seal arrangements.
Fig. 3 shows a detailed section of a connection to an intermediate seal arrangement.
Figs 4a to 4e show partial section views (Figs 4a, 4b and 4e) and detailed section views (Figs 4c and 4d) of further embodiments of a high lift component.
Fig. 5 shows an aircraft comprising at least one high lift component according to the invention.
Fig. 6 shows a diagrammatic block-based view of a method according to the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Fig. 1a shows a wing 2 on which as an example high lift components 4 are arranged side by side. As a result of static and dynamic lift-induced loads acting on the wing 2, during operation of the aircraft significant deflection can occur, which deflection manifests itself in upwards movements and downwards movements of a wing tip 6. To prevent damaging the high lift components 4 during such behavior of the wing 2, for example by mutual friction or mutual striking of lateral surfaces 8, gaps 10 are provided between the high lift components 4.
The high lift components 4 contribute to increasing the lift of the wing 2 in that both the surface and the curvature of the wing 2 are increased. However, the gaps 10 are associated with a disadvantage in that they let an airflow pass through, which results in a reduction in the effectiveness of the high lift components 4.
As shown in Fig. 1b the gap 10 can be closed by an intermediate seal 12. Consequently a largely closed surface between the high lift components 4 is present at all times so that the effectiveness of a high lift system with such high lift components 4 can be increased.
As also shown in Fig. 1b, the gap 10 has a tapered shape, wherein the intermediate seal 12 is sufficiently elastic to completely close both a wider end 14, which faces, for example, downstream, and a narrower end 16. Dynamic movement of a wing 2 with high lift components 4 arranged thereon and with intermediate seals 12 according to the invention can correspondingly also be operated in a particularly effective manner in the case of variable gap geometries.
Fig. 1c shows a section of the intermediate seal 12. The illustration shows sections of two high lift components 4, arranged side by side, with lateral surfaces 8 facing each other, on which lateral surfaces 8 in each case, as an example, two spaced-apart sections of hollow bodies 18 and 20 are shown which touch the respective corresponding hollow bodies 20 or 18. According to the invention, the hollow bodies 18 and 20 comprise a fluid that preferably comprises a certain compressibility so that an elastic spring-like behavior of the hollow bodies results. The material of the hollow bodies is preferably a synthetic material in the form of an elastomer or of a thermoplastic material that provides adequate elasticity even at low temperatures and which does not tend to become brittle.
Preferably, the entire gap 10 is sealed by means of an intermediate seal. Depending on a profile thickness d of the high lift components 4 and thus of the area of the lateral surfaces 8, an intermediate seal 12 can comprise a greater or lesser distance of one or several hollow bodies. Preferably, as shown in Fig. 2a, there is an extension of a hollow body 22 on a path near the edge on the respective edge area 8, which path comprises a largely closed circumference.
In an alternative variant from Fig. 2b, while a hollow body 24 is arranged on the lateral surface 8 near the edge, said hollow body extends, however, only in the region of a leading edge 26 and on one side to a trailing edge 28 and is open in some regions. This variant may make sense, in particular, in the case of dimensions of the high lift component 29, which dimensions are too narrow for the integration of a hose-like hollow body 22 as shown in Fig. 2a with a largely closed circumference.
It cannot be assumed that the hollow bodies shown, after single filling with a suitable fluid, always provide adequate tension that permits flexible sealing of the respective gap 10. For this purpose a fluid connection 34 may be provided on a hollow body 30 or 32, shown in Fig. 3, which fluid connection 34 comprises a filler neck 38 that is bonded or welded to the respective hollow body 30 or 32 in a fluid-proof manner. A free end is used to accommodate a fluid line 36 that can also be bonded to or welded to the filler neck 38; or as an alternative is mounted by means of a clamping assembly.
The neck 38 extends, for example, through a wall 40 into the interior of the high lift component 4, wherein the wall 40 has been implemented as a recess whose floor is offset back to the lateral area 8 of the high lift component 4. In the diagram the hollow bodies 30 and 32 comprise a width b that is greater than the extension h, defined by the wall 40, into the interior of the high lift components 4. Consequently, when viewed from the respective wall 40, said hollow bodies 30 and 32 project somewhat beyond the lateral surface 8 in order to provide a sealing face. Furthermore, by positioning it in a recess, the hollow body can be prevented from sliding out. In this arrangement the recess can continue to determine the path of extension of the hollow bodies 30 and 32.
For example a pump or a blower within the high lift component 4 or within the wing 2 or in some other position inside or outside the aircraft fuselage may be used as a suitable fluid source, wherein ambient air may be used as a fluid. As an alternative, it would also be possible to use compressed-gas tanks that may be regularly filled up or exchanged.
In a totally different exemplary embodiment according to Figures 4a to 4d, hollow bodies 43 are connected to a passage 42 that extends from an outer lower surface 46 of a high lift component 44, which outer lower surface 46 in an extended state at least in some regions faces downstream, into the interior of said high lift component so that on the aforesaid a pressure differential between a static and a dynamic pressure is present along the respective high lift component 44 for introducing air into hollow bodies of an intermediate seal. In this arrangement the high lift component 44 is, in particular, designed as a Krueger flap that in a stowed-away position is arranged on an underside of the wing 2 in a recess 48, and during activation is deflected by way of adjustment kinematics against the direction of airflow in the direction of flight x, wherein onwards from a certain deflection point on the underside of the high lift component 44 the pressure is higher than in the interior of the aforesaid, which can be utilized for inflating the hollow bodies. Furthermore, this embodiment is associated with a particular advantage in that when the high lift component 44 is arranged in a stowed-away position the passage 42 that extends into the interior is closed by the bottom surface of the recess on the underside of the wing, and consequently there is no influence on the airflow during cruise flight.
As shown in Figs 4c and 4d, it is also possible to use valves 47 and 49 that are designed either as nonreturn valves or as switching valves. The switching valve can be connected to a control unit 51, with said switching valve being opened, for example, if a setpoint position of the high lift component 44 is reached when adjacent high lift components have travelled along the longest displacement path. The corresponding signal can take place automatically from a flight control system.
Of course, an intermediate seal 12 according to the invention can also be implemented with the use of hollow bodies that are not of a hose-like design but instead are larger-areas, individual, and shape-adapted pillow-like hollow bodies, wherein this might possibly result in weight disadvantages and would require a larger fluid volume. However, as a result of a larger extension it would also be possible to use greater wall thicknesses for the hollow bodies, which in turn results in improved wear resistance and thus improved service life. The deformation behavior may improve as a result of the spatially increased extension of the intermediate seal 12, and in addition the area contact would be better, when compared to hose-like bodies, in particular in the case of different displacement speeds between adjacent high lift components.
It would also be possible to use a pitot tube 19 as a fluid source, which pitot tube 19 in Fig. 4e is connected to a hose-like hollow body 43 of a high lift component 41. By subjecting the pitot tube 19 to an airflow, on a fluid inlet a pressure can be generated that is higher than the ambient pressure.
Fig. 5 shows an aircraft 56 comprising a high lift system 50 that comprises a number of high lift components 52 and 54 with intermediate seals 12.
The method according to the invention, shown in Fig. 6, for adjusting the high lift characteristics of an aircraft comprises, as an example, the steps of extending 56 two adjacent high lift components 4, 29, 31, 41, 44 of the aircraft from a retracted position to an extended position, and of expanding 58 at least one intermediate seal 12, 25, 33, which in the extended position of both high lift components 4, 29, 31, 41, 44 is located between the high lift components 4, 29, 31, 41, 44, so that in the extended position of the high lift components 4, 29, 31, 41, 44 the at least one intermediate seal 12, 25, 33 is expanded in such a manner that the space between the high lift components 4, 29, 31, 41, 44 is essentially closed by the at least one intermediate seal 12, 25, 33. As an example, the method involves introducing 60 fluid into at least one hollow body 18, 20, 24, 30, 32, 43 of the intermediate seal, wherein this can comprise introducing 62 ram air. As described above, introducing 62 ram air can take place by way of a passage 42 or a pitot tube 19. Controlling 64 a valve for opening and closing makes it possible to selectively introduce fluid into the intermediate seal.

Claims

A high lift component (4, 29, 31, 41, 44), comprising at least one intermediate seal (12, 25, 33) on at least one lateral surface (8), wherein the intermediate seal (12, 25, 33) comprises at least one hollow body (18, 20, 24, 30, 32, 43) made of an elastic material, characterised in that the hollow body (18, 20, 24, 30, 32, 43) comprises a fluid inlet (34) that is connectable to a fluid source.
The high lift component (4, 29, 31, 41, 44) of claim 1, wherein the hollow body (18, 20, 24, 30, 32, 43) of the intermediate seal (12, 25, 33) is a hose-like body that is arranged along a largely closed path on the lateral surface (8) of the high lift component (4, 29, 31, 41, 44).
The high lift component (44) of claim 1 or 2, further comprising an upper outer surface (45) which in an extended state at least in some regions faces upstream, and a lower outer surface (46) which in an extended state at least in some regions faces downstream, wherein a passage (42) extends as a fluid source from the lower surface (46) or from the upper surface (45) into the interior of the high lift component (44), wherein the fluid inlet (34) is situated in the interior of the high lift component (44) and is connected to the end of the passage (42), which end projects into the interior of the high lift component (44).
The high lift component (44) of any one of the preceding claims, designed as a Krueger flap which on its surface that in an extended state is the lower surface (46) and that at least in some regions faces upstream comprises a passage (42) connected to the fluid inlet.
The high lift component (44) of claim 3 or 4, further comprising a valve (47, 49) that is connected to the passage (42).
The high lift component (44) of claim 5, wherein the valve (49) is a switching valve or regulating valve that for the purpose of selectively introducing fluid into the hollow body (43) is connected to a control unit (51).
The high lift component (41) of any one of the preceding claims, wherein the fluid source is designed as a pitot tube (19) that is positionable on an outside of the high lift component (41), of the superordinate wing or of some other part of the aircraft concerned, and that is connectable to the fluid inlet of the hollow body (43) by way of a fluid line.
The high lift component (4, 29, 31, 41, 44) of any one of the preceding claims, wherein the hollow body (18, 20, 24, 30, 32, 43) is of a hose-like design, comprises two closed ends, and extends along a path on the lateral surface of the high lift component (4, 29, 31, 41, 44), which path on a the border Z is configured to extend along the upper outer surface and a wing leading edge.
The high lift component (4, 29, 31, 41, 44) of any one of the preceding claims, wherein the hollow body (18, 20, 24, 30, 32, 43) is arranged so as to be largely flush with the profile contour.
A method for adjusting the high lift characteristics of an aircraft, comprising the steps of:
- extending (56) two adjacent high lift components (4, 29, 31, 41, 44) of the aircraft from a retracted position to an extended position,

- while extending (56) the two high lift components (4, 29, 31, 41, 44), expanding (58) at least one intermediate seal (12, 25, 33) that in the extended position of both high lift components (4, 29, 31, 41, 44) is located between the high lift components (4, 29, 31, 41, 44) so that in the extended position of the high lift components (4, 29, 31, 41, 44) the at least one intermediate seal (12, 25, 33) is expanded in such a manner that the space between the high lift components (4, 29, 31, 41, 44) is essentially closed by the at least one intermediate seal (12, 25, 33).
The method of claim 10, further comprising the step of:
- introducing (60) fluid into at least one hollow body (18, 20, 24, 30, 32, 43) of the intermediate seal (12, 25, 33).
The method of claim 10 or 11, wherein introducing (60) fluid includes introducing (62) ram air.
An aircraft (56), comprising at least one high lift component (4, 29, 31, 41, 44) of any one of claims 1 to 9.